1. Field of the Invention
The present invention relates to the field of compositions which may be applied to a tooth and methods for applying a composition to a tooth to alter the appearance thereof or provide a treatment to the tooth.
2. Brief Description of the Prior Art
Many procedures are done to improve the appearance of teeth. Teeth are filled to replace dentin and enamel invaded by bacteria, and can be capped to replicate a removed or abraded portion of a tooth.
The teeth of individuals widely vary in their appearance and shape. This is due to the genetic make-up of the individual, but can also be affected by age, and the degree of contact with various foods and medications, both those superficially contacting the teeth and from the internal effects of the medication. The teeth of some individuals exhibit a yellow appearance while those of others may be whiter. While aging is often considered a xe2x80x9cnaturalxe2x80x9d cause of tooth discoloration, other factors commonly attributed to tooth discoloration can include chemical exposure to tannins, which are found in red wines, and brewed beverages such as coffees and teas. Additional discoloring chemicals include those not naturally occurring in foods, but rather, manufactured or synthesized compounds, such as, for example, the compounds found in medications, like antibiotics, including tetracycline and other pharmaceuticals. The common practice of using doses of tetracycline to cure facial, acne blemishes has been known to contribute to the discoloration of teeth. Aside from these chemicals, even excess brushing can create discoloration by repeated contact with fluoride compounds commonly present in most toothpastes.
Many have attempted to confront the problem of tooth discoloration by proposing various solutions to whiten the teeth. One such method of tooth whitening involves the bonding of veneers onto the buccal or labial surfaces of a tooth. The veneer is usually constructed and applied by a dentist using dental bonding techniques to attach it to the tooth. Various veneers have been described in several U.S. Patents, see, e.g. U.S. Pat. No. 4,992,049 xe2x80x9cMethod for Applying a Veneer Facing to a Toothxe2x80x9d; U.S. Pat. No. 4,822,279 xe2x80x9cArticle for Cosmetic Restoration of Anterior Teethxe2x80x9d (which uses a glazed porcelain labial veneer); U.S. Pat. No. 4,682,950 xe2x80x9cDevice and Method of Bonding and Veneering Dental Material to a Toothxe2x80x9d (syringing composite material to a tooth surface which has been etched and coated with a bonding material); U.S. Pat. No. 4,473,353 xe2x80x9cMethod for Cosmetic Restoration of Anterior Teethxe2x80x9d (wherein a glazed porcelain veneer is bonded to a patient""s tooth); and U.S. Pat. No. 4,433,959 xe2x80x9cComposite Laminate Dental Veneer Containing Color Systemsxe2x80x9d (a veneer which is molded and then attached to the labial enamel surfaces of teeth).
Other attempts to whiten teeth are also known to include bleaching the teeth. Often the bleach is applied in the form of hydrogen peroxide, which can be obtained in drug stores by consumers. Because of the delicacy of applying hydrogen peroxide in one""s mouth, some dentists carry out the procedure in their offices, using a stronger peroxide than can be purchased by the consumer. There are even pastes, sold over the counter, to the consumers which claim to whiten teeth. Often ordinary toothpastes make this claim, but increasingly appearing in the marketplace for purchase by consumers are pastes with the chemical compound sodium bicarbonate (baking soda), which may also contain peroxide. While chemical bleaching of teeth has been done to provide whiter looking teeth, with its use there exists danger to the enamel of the teeth, especially if excessive exposure to chemical bleaches occurs. Further, chemical bleaching is understood in many cases to require multiple applications, and, hence, repeated use of the chemical. Even when applied by a dentist, precautions may be taken to prevent peroxide solution from contacting the patient""s gums, which if otherwise allowed to come into contact therewith can be painful and cause damage to the gums. In cases of certain stains, bleaching may not be effective, and the stain may remain.
There are even procedures involving abrasion of the tooth enamel to present a smooth surface which is lighter in appearance than the stained surface removed. This has limitations as to the number of times it can be done.
Furthermore, abrading or bleaching teeth can have deleterious side effects, including increased sensitivity of the treated tooth to temperature, i.e. especially when hot and cold foods and drinks are consumed. This effect may subside within time, but often the need to repeat bleaching procedures regularly, gives rise to a period of time within which the treated tooth can be hypersensitive.
There are some prior art whitening methods which require etching steps that are carried out with phosphoric acids. The use of phosphoric acid is generally done by a dentist under controlled conditions, for example, in the dentist""s office. Caustic acid etchants have been recognized to be corrosive to the soft tissues of the mouth. For example, ortho-phosphoric acid, in some venues, must be transported pursuant to specified requirements and restrictions. In addition, the long term physiological effects of acid etching, which are generally unknown, have led practitioners to question certain acid etching uses in the field of dentistry. See e.g. M. G. Buonocore, xe2x80x9cThe Challenge of Bonding to Dentinxe2x80x9d, The Acid Etch Technique, L. M. Silverstone and I. L. Dogon, Eds., Proceedings of the International Symposium at St. Moritz, Switzerland, Dec. 16-18, 1974, North Central Publishing Co. (St. Paul, 1975). See also, U.S. Pat. No. 5,304,585, which raises these concerns, the complete disclosure of which is herein incorporated by reference; and see Akira Komori, and Haruo Ishikawa, xe2x80x9cEvaluation of a Resin-Reinforced Glass Ionomer Cement for Use as an Orthodontic Bonding Agent,xe2x80x9d The Angle Orthodontist, Vol. 67 No. 3, 1997, the complete disclosure of which is herein incorporated by reference. Further attempts to whiten teeth are disclosed in U.S. Pat. No. 4,032,627 xe2x80x9cTooth Whitening Cosmetic Compositionxe2x80x9d; U.S. Pat. No. 4,097,994 xe2x80x9cDental Restorative Composition Containing Oligomeric Bis-GMA Resin and Michler""s Ketonexe2x80x9d; U.S. Pat. No. 4,141,144 xe2x80x9cDental Material and Method for Controlling Tooth Lustrexe2x80x9d; and U.S. Pat. No. 4,512,743 xe2x80x9cMethod for Masking Discoloration on Teeth.xe2x80x9d U.S. Pat. Nos. 4,512,743 and 4,141,144, each use phosphoric acid application to the tooth in their treatments. U.S. Pat. No. 4,097,994 discloses a photocurable compound, which is used with a specific ultraviolet sensitizer and a peroxide catalyst to cure the compound. Furthermore, phosphoric acid etching generally disposes grooves in the tooth enamel in the nature of about 50 to 60 xcexcm. This order of etching is visible and is noticed in the form of a dull tooth surface.
U.S. Pat. No. 4,032,627, referenced above, discloses the use of an alcohol-soluble composition to be applied to the surface of a tooth to whiten the tooth""s appearance. This composition is suggested to be applied by the user. However, although this disclosure attempts to provide an extended wearing time for its compound, the composition is readily worn off by the abrasive action of food eaten after the compound is applied to the teeth, with certain, more abrasive, harder, foods causing faster wear of the composition from the tooth than other, softer foods.
The human body relies upon hydroxyapatite as the principal crystal for all calcified tissue. Hydroxyapatite is also found in teeth. Fluoride ion reacts with the hydroxyapatite in teeth. During the formation of teeth, generally in children, fluoride is known to improve the tooth""s resistance to dental caries by reacting with the hydroxyapatite to form a more caries-resistant tooth. The reaction of hydroxyapatite with fluoride results in the formation of fluorapatite. The reaction equation is set forth below:
Ca10(PO4)6(OH)2+2Fxe2x88x92- - - greater than Ca10(PO4)6F2+2OH31 
While fluoride deposition may occur while teeth are being formed, before teeth appear in a child""s mouth, low levels of fluoride in the tissue fluids are incorporated into the enamel crystals. Fluoride deposition continues in the enamel, and once the teeth erupt from the gums and become exposed in a child""s mouth, the surface enamel can take up fluoride from sources such as drinking water (if fluoridated) and food.
Treatment agents such as fluoride are applied to teeth in a medical office under the supervision of medical personnel such as a dentist. Fluoride can be dangerous if mishandled or ingested in excess quantities. Dental applications have comprised inserting a mouth piece in a patient""s mouth and filling the mouth piece with a fluoride containing liquid which contacts the patient""s teeth during the time in which the mouth piece remains inserted. This procedure is carried out by a dentist, is time consuming and can be uncomfortable for the patient. Also, teeth may not be fully covered due to the level which the mouthpiece can hold. While commercially available consumer products such as tooth pastes and rinses which contain fluoride have been provided for sale to the consumer directly, the amount of time that the fluoride containing composition is actually in contact with the teeth is minimal. This is purposefully done so as to avoid potentially harmful effects of fluoride poisoning. Although, fluoride is a known substance which is beneficial to teeth when topically applied to the tooth""s surface in a known amount, fluoride can be toxic, and in certain doses, even fatal. A need therefore exists to provide fluoride in a beneficial amount where the fluoride application is controlled and the possibility of fluoride poisoning is reduced. It is desirable to provide a composition and method for covering a tooth, to appear white or colorized, which contains fluoride and can be selectively applied and removed by a user or non-medical personnel without harming the tooth or the individual wearer
A novel composition and method for improving or altering the appearance of teeth is provided by the present invention, where an individual, in his or her own home, a doctor""s office, or even a non-medical office, can apply a compound to his or her teeth to alter the tooth by covering the tooth with a composition to alter the appearance of the tooth, such as by colorizing the tooth and/or applying a design or indicia on the tooth. A treatment agent may also be administered to the tooth with the composition, and a method is provided for administering a treatment agent to teeth. The present method can be used to colorize and/or treat teeth, and may even be done in the presence of existing saliva which may be present on the tooth. The method provides a removable coating which may comprise a colorized or non-colorized coating which can be removed and replaced with other colorized coatings, or no further coatings, at the user""s discretion. Expensive or dangerous drying apparatus are not required. Further, the composition of the present invention may be applied with or without an etching step, thereby avoiding the hazards inherent to use of caustic acid etchants, such as phosphoric and phosphonic acids. Moreover, when an individual""s teeth, in accordance with the present method, require pre-treatment prior to application of the covering compound, the application of a naturally occurring substance can be used to facilitate adhesion. The substance can be lemon juice or lime juice, which unlike caustic acids, contains citric acid, which can be purchased by the consumer user of the covering compound which is to be applied by the present method. In a proposed alternate embodiment of the invention, polyacrylic acid is applied to the tooth surface prior to contact with the covering compound.
The present invention also provides a novel composition and method for temporarily changing the color of a tooth on which the treatment is being applied.
A palette system may be provided wherein a user or wearer can select a color from one, or a combination of one or more, colorizing compounds. The selected or created color can then be incorporated with the other steps of the present method to provide a unique appearance to a tooth. The present method permits the user to mix his or her own colors or to select a color from one or more prepared provided colors. In the case where a treatment agent is present in the compound to be applied to the tooth, the color corresponds to the area of the tooth being treated.
A masking material, which preferably may comprise a film, may be applied onto the surface of a tooth to temporarily remain thereon so that the covering compound can be applied over the stencil to create a design or other indicia on the tooth.
The composition is a removable compound. Preferably, the composition includes a lac material, a colorant, a polysaccharide or phospholipid compound or both, and a solvent such as ethanol. Lac, the natural resinous substance excreted by an insect, Laccifer Lacca, has been used in dentistry mainly for the construction of special trays and bases for wax rims when recording jaw relationships. (See A. Azucca, R. Huggett, and A. Harrison, xe2x80x9cThe Production of Shellac and its General and Dental Uses: A review.xe2x80x9d Journal of Oral Rehabilitation, 1993, vol. 20, pp. 393-400, the complete disclosure of which is herein incorporated by reference; and I. Klineberg and R. Earnshaw, xe2x80x9cPhysical Properties of Shellac Baseplate Materials.xe2x80x9d Australian Dental Journal, October, 1967, vol. 12 no. 5, pp. 468-475.) Another use of shellac in dentistry includes treatment of a cavity with a hydrophilic shellac film placement of a polystyrene liner. (See M. Blixt and P. Coli, xe2x80x9cThe Influence of Lining Techniques on the Marginal Seals of Class 11 Composite Resin Restorationsxe2x80x9d Quintessence International, vol. 24, no. 3, 1993). Shellac has also been prepared and used in dentistry for the use of a bead adhesive for securing a composite resin veneer cast restoration. (See C. Lee, H. Pierpont, and E. Strickler, xe2x80x9cThe Effect of Bead Attachment Systems on Casting Patterns and Resultant Tensile Bond Strength of Composite Resin Veneer Cast Restorationsxe2x80x9d, The Journal of Prosthetic Dentistry, November, 1991, vol. 66, no. 5, pp. 623-630.)
In the embodiment where a treatment agent is present, the treatment agent preferably comprises fluoride or a fluoride containing compound which is mixed together with the lac resin.
It is an object of the present invention to provide a novel composition and method for improving the appearance and character of teeth.
It is a further object of the present invention to provide a composition and a method that can be useful for whitening teeth to improve or alter their appearance.
It is a further object of the present invention to improve or alter the appearance of teeth by covering stains or discolorations on a tooth by matching a colorized compound to an individual""s teeth and applying the colorized compound containing the treatment agent on the surface of said stained or discolored teeth.
A further object of the present invention is to improve the appearance of a tooth by applying a colored or shaded composition to the tooth.
A further object of the present method is to change the appearance of a tooth by applying a colored or shaded composition containing a treatment agent to the tooth.
A further object of the present method is to match the appearance of a tooth to surrounding or adjacent teeth by applying a colored or shaded composition.
A further object of the present invention is to coordinate colors of a tooth with other health and beauty aids by applying a colorizing compound to a tooth.
Another object of the present invention is to provide a method for applying a compound containing a treatment agent to a tooth which can remain on the tooth during eating and other activity, and can be removed at the wearer""s discretion, to leave the tooth as it appeared before the application of the compound.
A further object of the present invention is to provide a novel method of altering the appearance of a tooth which includes applying a compound to the tooth and selectively removing the compound from the tooth.
A further object of the present invention is to provide a method for altering the appearance of a tooth which can be repeated by the wearer, to change the appearance of a tooth, on a regular basis if the wearer desires, without having damaging effects on the tooth enamel.
Another object of the present invention is to provide a method which includes a color matching system wherein the user mixes components to colorize the composition containing a treatment agent to be applied to the tooth to the desired hue or color, which can be a tooth color or a non-tooth color.
It is another object of the present invention to accomplish the above objects by repeating application and removal of the compound containing a treatment agent on a tooth for different colors as the user determines and selects.
Another object of the present invention is to provide a tooth covering composition which can be selectively colorized, applied and removed by a user.
It is a further object of the present invention to provide a composition and a method that can be useful for delivering a treatment agent.
Another object of the present invention is to accomplish any of the above objects using a stencil to create a design or other indicia on a tooth.
Another object of the present invention is to provide a method and components for applying a design or other indicia to a tooth.
Another object of the present invention is to provide a compound which may be selectively removed from the tooth by a forced stream of water.